Riots and street battles killed at least 156 people in China's western Xinjiang province, state media said Tuesday, and injured 828 others in the deadliest ethnic unrest to hit the region in decades. Officials said the death toll was expected to rise.

Police sealed off streets in parts of the provincial capital, Urumqi, after discord between ethnic Muslim Uighur people and China's Han majority erupted into violence. Witnesses reported a new, smaller protest Monday in a second city, Kashgar.

The unrest is another troubling sign for Beijing at how rapid economic development has failed to stem — and even has exacerbated — resentment among ethnic minorities, who say they are being marginalized in their homelands as Chinese migrants pour in.

Columns of paramilitary police in green camouflage uniforms, helmets and flak vests marched Monday around Urumqi's main bazaar — a largely Uighur neighborhood — carrying batons and shields. Mobile phone service and the social networking site Twitter were blocked, and Internet links were also cut or slowed down.

Rioters on Sunday overturned barricades, attacked vehicles and houses, and clashed violently with police in Urumqi, according to media and witness accounts. State television aired footage showing protesters attacking and kicking people on the ground. Other people, who appeared to be Han Chinese, sat dazed with blood pouring down their faces.

In a one-sentence reported released early Tuesday, the official Xinhua News Agency said 156 people had died. There was little immediate explanation for the high death toll and officials did not say how many of the victims were Han or Uighurs. Xinhua cited Xinjiang's police chief Liu Yaohua as saying that the death toll was expected to rise.

The government accused a Uighur businesswoman living in the U.S. of inciting the riots through phone calls and "propaganda" spread on Web sites.

Witnesses and state media said the violence started only after police arrived to disperse a peaceful protest demanding justice for two Uighurs killed last month during a fight with Han co-workers at a factory in southern China.

Thousands of people took part in Sunday's disturbance, unlike recent sporadic separatist violence carried out by small groups in Xinjiang. The clashes echoed the violent protest that rocked Tibet last year and left many Tibetan communities living under clamped-down security ever since.

Tensions between Uighurs and the majority Han Chinese are never far from the surface in Xinjiang, a sprawling region rich in minerals and oil that borders eight Central Asian nations. Many Uighurs (pronounced WEE-gers) yearn for independence and some militants have waged a sporadic, violent separatist campaign.

Uighurs make up the largest ethnic group in Xinjiang, but not in the capital of Urumqi, which has attracted large numbers of Han Chinese migrants. The city of 2.3 million is now overwhelmingly Chinese — a source of frustration for native Uighurs who say they are being squeezed out.

Kakharman Khozamberdi — leader of a Uighur political movement in Kazakhstan, where the Uighur minority has its largest presence outside China — said machine gun fire was heard all night long. One witness told Khozamberdi 10 bodies were seen near a bazaar, including those of women and children.

In Geneva, U.N. Secretary-General Ban Ki-moon urged China and any country with violent protests to use extreme care. He urged all governments to "protect the life and safety of civilians."

About 1,000 to 3,000 Uighur demonstrators had gathered Sunday in the regional capital for a protest that apparently spun out of control. Accounts differed over what happened, but the violence seemed to have started when the crowd of protesters refused to disperse.

Xinhua reported hundreds of people were arrested and checkpoints ringed the city to prevent rioters from escaping. Mobile phone service provided by at least one company was cut Monday to stop people from organizing further action in Xinjiang.

Internet access was blocked or unusually slow in Urumqi on Monday. Videos and text updates about the riots were removed from China-based social networking sites such as Youku, a YouTube-like video service, and Fanfou, a Chinese micro-blogging Web site similar to Twitter.

Major Chinese news portals relied solely on Xinhua for news of the event and turned off the comment function at the bottom of the stories so people could not publicly react.

Witnesses said the protests spread to Kashgar, a second city in Xinjiang, on Monday afternoon. A Uighur man there said he was among more than 300 protesters who demonstrated outside the Id Kah Mosque. He said they were surrounded by police, who asked them to calm down.

"We were yelling at each other but there were no clashes, no physical contact," said the man, who gave his name as Yagupu.

Calls to Kashgar's public security bureau rang, then were disconnected.

Uighur activists and exiles say the millions of Han Chinese who have settled here in recent years are gradually squeezing the Turkic people out of their homeland.

But many Chinese believe the Uighurs are backward and ungrateful for the economic development the Chinese have brought to the poor region.

Wu Nong, director of the news office of the Xinjiang provincial government, said more than 260 vehicles were attacked or set on fire in Sunday's unrest and 203 shops were damaged.

Uighur exiles condemned the crackdown.

"We ask the international community to condemn China's killing of innocent Uighurs. This is a very dark day in the history of the Uighur people," said Alim Seytoff, vice president of the Washington, D.C.-based Uyghur American Association.

Chinese officials singled out the leader of the association — Rebiya Kadeer, a former prominent Xinjiang businesswoman now living in Washington — for inciting the violence.

"Rebiya had phone conversations with people in China on July 5 in order to incite, and Web sites ... were used to orchestrate the incitement and spread propaganda," Xinjiang Governor Nur Bekri said on television early Monday.

Xinjiang's top Communist Party official, Wang Lequan, called the riots "a profound lesson learned in blood."

"We must tear away Rebiya's mask and let the world see her true nature," Wang said.

The government has accused Kadeer of having a hand in many of Xinjiang's problems since her release from prison into U.S. exile in 2005. The Foreign Ministry has publicly accused the 62-year-old of having links to the East Turkestan Islamic Movement, a group the U.S. put on its terrorist blacklist.

Beijing has not provided evidence to support the allegation, and Kadeer denies the claim. She has repeatedly called for nonviolent protest.

On "Oriental Horizon," a current affairs program aired on China Central Television on Monday night, a scholar from the government's Chinese Academy of Social Science blamed Kadeer for masterminding the riots.

The half-hour program, which was devoted to the Urumqi violence, also showcased footage shown on earlier newscasts.

The clashes in Urumqi echoed last year's unrest in Tibet, when a peaceful demonstration by monks in the capital of Lhasa erupted into riots that spread to surrounding areas, leaving at least 22 dead. The Chinese government accused Tibet's exiled spiritual leader, the Dalai Lama, of orchestrating the violence — a charge he denied.

Seytoff said he had heard from two sources that at least two dozen people had been killed by gunfire or crushed by armored police vehicles just outside Xinjiang University.

"First they fired tear gas at the students. Then they started beating them and shooting them with bullets. Big trucks arrived, and students were rounded up and arrested," Mamet said.

Previous mass protests in Xinjiang that were quelled by armed forces became signal events for the separatist movement. In 1990, about 200 Uighurs shouting for holy war protested through Baren, a town near the Afghan border, resulting in violence that left at least two dozen people dead.

In 1997, amid a wave of bombings and assassinations, a protest by several hundred Uighurs in the city of Yining against religious restrictions turned into an anti-Chinese uprising that left at least 10 dead.

In both cases pro-independence groups said the death tolls were several times higher, and the government never conducted a public investigation into the events.

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